Two-mode trocar assembly

ABSTRACT

An obturator assembly for penetrating tissue and being at least partially positionable within a cannula assembly includes an obturator housing, an obturator shaft connected to the obturator housing and defining a longitudinal axis, a penetrating member adjacent the distal end of the obturator shaft and an obturator shield mounted about the obturator shaft and having a distal shield nose. The obturator shield is adapted for longitudinal movement between an extended position where the penetration member is substantially enclosed within the shield nose and a retracted position where the penetrating member is at least partially exposed from the shield nose. A manually manipulative member is mounted to the obturator housing and is adapted for rotational movement about the longitudinal axis and relative to the obturator housing between an initial position corresponding to a first mode of operation where the obturator shield is secured in the extended position and the shield nose is used to penetrate tissue, and a release position corresponding to a second mode of operation operatively releasing the obturator shield to permit the obturator shield to move to the retracted position thereof to expose the penetrating member for penetrating the tissue. The obturator assembly may further include a latch member disposed within the obturator housing. The preferred latch member is in operative engagement with the obturator shield to secure the obturator shield in the extended position thereof. The latch member is actuable to release the obturator shield when the obturator housing is mated with the cannula assembly to thereby permit movement of the obturator shield toward the retracted position provided the manually manipulative member is in the release position. The obturator assembly further includes a release member which is mounted to the obturator housing and operatively coupled with the latch member. The release member is positioned to engage the cannula assembly upon mating of the obturator housing and the cannula assembly to thereby displace the release member and cause actuation of the latch member.

BACKGROUND

1. Technical Field

This application claims the benefit of U.S. Provisional PatentApplication No. 60/819,244 filed Jul. 6, 2006, the entire disclosure ofwhich is incorporated by referenced herein.

2. Background of the Related Art

Minimally invasive procedures are continually increasing in number andvariation. Forming a relatively small diameter temporary pathway to thesurgical site is a key feature of most minimally invasive surgicalprocedures. The most common method of providing such a pathway is byinserting a trocar assembly through the skin. In many procedures, thetrocar assembly is inserted into an insufflated body cavity of apatient. In such procedures, the trocar assemblies with seal mechanismsare utilized to provide the necessary pathway to the surgical site whileminimizing leakage of insufflation gases.

Trocar assemblies typically include an obturator which is removablyinserted through a cannula. The obturator may include a safety shieldwhich protects against unintentional puncturing by the sharpened tip ofthe obturator. The safety shield includes a mechanism which controls therelative movement and locking of the safety shield. Examples of safetyshield mechanisms are disclosed in commonly assigned U.S. Pat. No.6,319,266 to Stellon et al., and commonly assigned U.S. application Ser.No. 11/171,052, filed Jun. 30, 2005, the entire contents of eachdisclosure being incorporated herein by reference.

SUMMARY

Accordingly, the present disclosure is directed to further improvementsin obturator assemblies. In one preferred embodiment, an obturatorassembly for penetrating tissue and being at least partiallypositionable within a cannula assembly includes an obturator housing, anobturator shaft connected to the obturator housing and defining alongitudinal axis, a penetrating member adjacent the distal end of theobturator shaft and an obturator shield mounted about the obturatorshaft and having a distal shield nose. The obturator shield is adaptedfor longitudinal movement between an extended position where thepenetration member is substantially enclosed within the shield nose anda retracted position where the penetrating member is at least partiallyexposed from the shield nose. A manually manipulative member is mountedto the obturator housing and is adapted for rotational movement aboutthe longitudinal axis and relative to the obturator housing between aninitial position corresponding to a first mode of operation where theobturator shield is secured in the extended position and the shield noseis used to penetrate tissue, and a release position corresponding to asecond mode of operation operatively releasing the obturator shield topermit the obturator shield to move to the retracted position thereof toexpose the penetrating member for penetrating the tissue. The obturatorassembly may further include a latch member disposed within theobturator housing. The preferred latch member is in operative engagementwith the obturator shield to secure the obturator shield in the extendedposition thereof. The latch member is actuable to release the obturatorshield when the obturator housing is properly mated with the cannulaassembly to thereby permit movement of the obturator shield toward theretracted position provided the manually manipulative member is in therelease position. The obturator assembly further includes a releasemember which is mounted to the obturator housing and operatively coupledwith the latch member. The release member is positioned to engage thecannula assembly upon mating of the obturator housing and the cannulaassembly to thereby displace the release member and cause actuation ofthe latch member.

An indicator member may be operatively connected to the obturatorshield. The indicator member is adapted for longitudinal movement withthe obturator shield to provide visual confirmation to the operator ofthe positioning of the obturator shield. The manually manipulativemember may be in operative engagement with the indicator member when inthe initial position of the manually manipulative member to secure theobturator shield in the extended position and is operatively disengagedfrom the indicator member when in the release position of the manuallymanipulative member to permit movement of the obturator shield to theretracted position. An indicator collar may be disposed within theobturator housing and mounted to the obturator shield. The indicatorcollar has the indicator member mounted thereto and is adapted forlongitudinal movement with the obturator shield.

Stop means may be associated with the obturator housing for confirmingpositioning of the manually manipulative member at the initial positionand the release position. Alternatively, a control member may be mountedin fixed relation to the obturator housing and operatively associatedwith the manually manipulative member. One of the control member and themanually manipulative member includes a groove and the other of thecontrol member and the manually manipulative member includes a pin. Thepin traverses the groove during rotation of the manually manipulativemember between the initial and release position thereof wherebyterminating ends of the groove correspond to the initial and releaseposition of the manually manipulative member.

The penetrating member is preferably an obturator blade connected to theobturator shaft. The obturator shield may be normally biased toward theextended position.

In another preferred embodiment, an obturator assembly for penetratingtissue and being at least partially positionable within a cannulaassembly includes an obturator housing defining a longitudinal axis, anobturator shaft connected to the obturator housing, a penetrating memberadjacent the distal end of the obturator shaft and an obturator shieldmounted about the penetrating member and having a shield nose adapted topenetrate tissue. The obturator shield is adapted for longitudinalmovement between an extended position where the shield nosesubstantially encloses the penetrating member and a retracted positionto at least partially expose the penetrating member. A latch member isdisposed within the obturator housing and in operative engagement withthe obturator shield to secure the obturator shield in the extendedposition thereof. The latch member is actuable to release the obturatorshield to permit movement of the obturator shield toward the retractedposition thereof. A manually manipulative member is mounted to theobturator housing and adapted to be selectively moved by the operatorrelative to the obturator housing between an initial positioncorresponding to a first mode of operation securing the obturator shieldin the extended position whereby the shield nose is utilized to passthrough tissue, and a release position corresponding to a second mode ofoperation operatively releasing the obturator shield to permit theobturator shield to move to the retracted position thereof provided thelatch member is actuated to expose the penetrating member to permit thepenetrating member to engage and pass through the tissue. The manuallymanipulative member may be adapted for rotational movement relative tothe obturator housing to move between the initial position and therelease position. A release member may be mounted to the obturatorhousing and operatively coupled with the latch member. The releasemember is positioned to engage the cannula assembly upon mating of theobturator housing and the cannula assembly to thereby displace therelease member and cause actuation of the latch member. An indicatormember may be operatively connected to the obturator shield. Theindicator member is adapted for longitudinal movement with the obturatorshield and for providing visual confirmation to the operator of thepositioning of the obturator shield. The manually manipulative member isin operative engagement with the indicator member when in the initialposition of the manually manipulative member to secure the obturatorshield in the extended position, and is operatively disengaged from theindicator member when in the release position of the manuallymanipulative member to permit movement of the obturator shield to theretracted position provided the latch member is actuated.

In another preferred embodiment, a trocar assembly includes a cannulaincluding a cannula housing and a cannula sleeve extending from thecannula housing and an obturator assembly at least partiallypositionable within the cannula. The obturator assembly includes anobturator housing, an obturator shaft connected to the obturatorhousing, an obturator blade connected to the obturator shaft and anobturator shield coaxially mounted about the obturator blade. Theobturator shield is adapted for longitudinal movement between a firstposition substantially enclosing the obturator blade and a secondposition to at least partially expose the obturator blade. A manuallymanipulative member is mounted to the obturator housing and is adaptedto be selectively moved by the operator relative to the obturatorhousing between an initial position corresponding to a first mode ofoperation where a generally blunt leading end of the obturator shield isused to penetrate tissue, and a release position corresponding to asecond mode of operation operatively releasing the obturator shield topermit the obturator shield to move to the retracted position thereof toat least partially expose the obturator blade for piercing throughtissue. A latch member is disposed within the obturator housing and inoperative engagement with the obturator shield to secure the obturatorshield in the extended position thereof. The latch member is actuable torelease the obturator shield upon approximating the obturator housingand the cannula housing. The manually manipulative member may be adaptedfor rotational movement relative to the obturator housing to movebetween the initial position and the release position.

Methods of use of the obturator assembly are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present disclosure are describedhereinbelow with references to the drawings, wherein:

Preferred embodiments of the present disclosure are describedhereinbelow with references to the drawings, wherein:

FIG. 1 is a perspective view of the trocar assembly in accordance withthe present disclosure, illustrating the cannula assembly and theobturator assembly;

FIG. 2 is a perspective view of the trocar assembly illustrating theobturator assembly assembled within the cannula assembly;

FIG. 3 is a perspective view with parts separated of the obturatorassembly;

FIG. 4 is a perspective view of the obturator housing of the obturatorassembly;

FIG. 5 is a second perspective view of the obturator housing of theobturator assembly;

FIG. 6 is a side cross-sectional view of the obturator housing of theobturator assembly illustrating the activator member in an initialposition corresponding to a first mode of operation of the obturatorassembly;

FIGS. 7-8 are perspective views of the obturator housing with thehousing cover removed;

FIG. 9 is an enlarged perspective view of the control member of theobturator housing;

FIGS. 10-11 are additional perspective views of the obturator housingwith the housing cover removed;

FIG. 12 is a side cross-sectional view of the obturator assemblyillustrating the latch member in an unactuated position;

FIG. 13 is an enlarged isolated view of the indicated area of detail ofFIG. 12 illustrating the relationship of the components of the latchmember in the unactuated position;

FIG. 14 is a side cross-sectional view of the trocar assemblyillustrating the obturator assembly mounted relative to the cannulaassembly and the latch member in an actuated position;

FIG. 15 is an enlarged isolated view of the indicated area of detail ofFIG. 14 illustrating the relationship of the components of the latchmember in the actuated position;

FIG. 16 is a side cross-sectional view of the obturator housingillustrating the activator member in a release position corresponding toa second mode of operation of the obturator assembly;

FIG. 17 is a side cross-sectional view similar to the view of FIG. 14illustrating the obturator shield of the obturator assembly in aretracted position to expose the obturator blade;

FIG. 18 is an enlarged isolated view of the indicated area of detail ofFIG. 17; and

FIG. 19 is a side cross-sectional view illustrating proximal movement ofthe indicator collar during movement of the obturator shield to theretracted position.

DETAIL DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now in detail to the drawing figures, in which like referencesnumerals identify similar or identical elements, there is illustrated,in FIGS. 1 and 2, a trocar assembly constructed in accordance with apreferred embodiment of the present disclosure, and designated generallyby reference numeral 10. Trocar assembly 10 is particularly adapted foruse in minimally invasive surgical procedures such as endoscopic orlaparoscopic procedures. Generally, trocar assembly 10 includes twoprincipal subassemblies, namely, obturator assembly 100 and cannulaassembly 1000.

Cannula assembly 1000 may be any cannula assembly suitable for use in alaparoscopic surgical procedure. In one preferred embodiment, cannulaassembly 1000 includes cannula housing 1002 and cannula sleeve 1004extending from the cannula housing 1002. Either or both cannula housing1002 and cannula sleeve 1004 may be opaque or transparent in part or inwhole and are fabricated from biocompatible metal or polymeric material.Cannula assembly 1000 may include an internal seal such as a duck-billvalve or other zero closure valve adapted to close in the absence of asurgical instrument to prevent passage of insufflation gases through thecannula assembly 1000.

Trocar assembly 10 may also include a seal assembly 2000 which ispreferably releasably mounted to cannula housing 1002. Means forreleasably connecting seal assembly 2000 to cannula housing 1002 mayinclude a bayonet coupling, threaded connection, latch, friction fit,tongue and groove arrangements, snap-fit, etc. Seal assembly 2000includes seal housing 2002 and at least one internal seal which isadapted to form a fluid tight seal about an instrument inserted throughthe seal assembly 2000. One suitable seal may be the fabric sealdisclosed in commonly assigned U.S. Pat. No. 6,702,787 to Racenet etal., the entire contents of which are incorporated herein by reference.The seal disclosed in the Racenet '787 patent may be a flat septum sealhaving a first layer of resilient material and a second fabric layerjuxtaposed relative to the first layer. Further details of the seal maybe ascertained by reference to the '787 patent. Seal assembly 2000 mayor may not be a component of cannula assembly 1000. For example, theseal assembly may be a separate, removable assembly. In the alternative,the seal assembly may comprise an integral part of the cannula assembly1000 and not be removable.

With reference now to FIG. 3, in conjunction with FIGS. 1-2, obturatorassembly 100 includes obturator housing 102, obturator shaft 104defining obturator axis “x” and extending distally from the housing 102and obturator shield 106 coaxially mounted about the obturator shaft104. In general, in a first preferred mode of operation, obturatorshield 106 defines a distal shield nose 206 which may be used to enter,penetrate or pass, etc. through tissue through a blunt or dissectionentry. Alternatively, in a second mode of operation, obturator shield106 is permitted to retract in a proximal longitudinal direction toexpose the cutting blade disposed at the distal end of the obturatorshaft 104. The details of operation and the configuration of shield nose206 and the cutting blade will be discussed hereinbelow.

Referring now to FIGS. 3-5, obturator housing 102 includes housing base108 and housing cover 110. Once the appropriate components arepositioned therewithin (as described below), housing base 108 may beattached to housing cover 110 by engaging mating surfaces, for example,by resilient depending latches 112 of cover 110 interlocking withcorrespondingly dimensioned latch openings 114 of housing base 108.Preferably, to uniformly connect base 108 and cover 110, at least threecorresponding latches 112 and openings 114 are spaced evenly around thecircumference of the cover 110 and the base 108, respectively.Preferably, obturator housing 102 is configured and dimensioned tofunctionally cooperate with cannulas that range in size, e.g., fromabout 5 mm to about 15 mm in diameter.

Referring now to FIGS. 4-7, in conjunction with FIG. 3, obturatorhousing 102 further includes dial or activator member 116 and controlmember 118 both of which are housed within the obturator housing 102.Activator member 116 defines activator disk 120 and activator collar 122extending distally from the activator disk 120. Activator disk 120defines raised tab 124 which is contoured for manual engagement by thefingers of the operator. Raised tab 124 extends beyond opening 126 ofhousing cover 110. Raised tab 124 further includes indicia in the formof recessed arrow 128 which identifies the status or position ofactivator member 116. Activator collar 122 includes axial slot 130 andaxial rib 132 (FIG. 7) in diametrical opposed relation to the axial slot130. Activator member 116 is adapted for limited rotational movement asdepicted by directional arrow “a” about longitudinal axis “x” betweeninitial and release positions to respectively secure and releaseobturator shield 106 (FIG. 4). The initial position of activator member116 corresponds to the first mode of operation of obturator assembly 100where obturator shield 106 is prevented from retracting and the distalshield nose 206 is used to pass through tissue. FIG. 6 illustrates theinitial position of activator member 116. The release positioncorresponds to the second mode of operation of obturator assembly 100where obturator shield 106 is permitted to retract and the cutting bladeis used to pierce through tissue.

With reference to FIGS. 6-9, in conjunction with FIG. 3, control member118 is fixed within obturator housing 102. Control member 118 includescontrol disk 134 and limiting collar 136 extending from the proximalside or face of control disk 134. Control disk 134 includes a pluralityof alternating tabs 138 and recesses 140 disposed along the outerperiphery of the control disk 134. Tabs 138 are received withincorresponding internal recesses 140 (FIG. 6) defined in the inner wallof housing cover 110 to secure control member 118 within obturatorhousing 102. Control member 118 also includes secondary aperture 142which is radially or laterally spaced from longitudinal axis “x”.Control disk 134 further includes cylindrical shaft mount 144 and springmount 146 both of which extend from the distal face of the control disk134. As best depicted in FIG. 6, shaft mount 144 is generally alignedwith longitudinal axis “x” and includes bifurcated tabs 148 and centralchannel 150. Spring mount 146 is laterally or radially spaced from thelongitudinal axis “x”.

With reference to FIG. 7, limiting collar 136 of control member 118 isdimensioned to receive activator collar 122 of activator member 116 inthe assembled condition of the components, and to permit the activatorcollar 122 to rotate within the limiting collar 136. Limiting collar 136defines recessed groove 152 which extends about ½ the perimeter of thelimiting collar 136. Axial rib 132 of activator member 116 traversesrecessed groove 152 of control member 118 during rotation of theactivator member 116 between the initial and release positions. As bestdepicted in FIG. 3, recessed groove 152 defines abutment walls 154, 156at each end of the recessed groove 152. Abutment walls 154, 156 serve asstop(s) to ensure and/or confirm placement of activator member 116 inthe initial or release position. Specifically, abutment walls 154, 156serve as a tactile indicator that activator member 116 has been moved toeither the initial or release position.

Referring now to FIGS. 3, 6, and 7, obturator housing 100 furtherincludes indicator collar 158. In one preferred arrangement, indicatorcollar 158 defines internal channel 160 and has distal collar extension162. Collar extension 162 includes inner tabs 164 on its inner surface.Indicator collar 158 further includes transverse arm 166 extendingradially outwardly from indicator collar 158 and shield positionindicator, such as indicator flag 168. Transverse arm 166 includes axialpin 170 which depends in a proximal direction from the arm 166. Axialpin 170 is in general axial alignment with secondary aperture 142 ofcontrol member 118 and traverses the secondary aperture 142 duringproximal movement of the indicator collar 158. Indicator flag 168 isvisible from the exterior of obturator housing 102 as it extends throughgroove 172 of housing cover 110 (see FIGS. 3 and 4). Preferably,indicator flag 168 is colored to contrast sharply with the surroundinghousing components. For example, indicator flag 168 may be red if thesurrounding housing components are white or light colored. As bestdepicted in FIG. 7, indicator collar 158 further includes collar ledge174 and a pair of posts 176 formed below the ledge 174 and extendingradially outwardly from the ledge 174.

As best depicted in FIG. 6, indicator collar 158 is spring biased in thedistal direction by coil spring 178. In particular, coil spring 178 isreceived within internal channel 160 of indicator collar 158 and engagesinternal shelf 160 s of the indicator collar 158. The proximal end ofcoil spring 178 is coaxially positioned about spring mount 144 dependingfrom the distal face of control member 118.

Referring now to FIGS. 10-13, in conjunction with FIG. 3, obturatorassembly 100 includes a latching mechanism disposed within obturatorhousing 102 to prevent proximal movement of obturator shield 106 untilsuch time as the obturator assembly 100 is properly mounted to cannulaassembly 1000 and the surgeon is prepared to begin trocar entry.Latching mechanism includes latch member 180, and release member such asslider 182. Latch member 180 has two vertical legs 184 connected by web186. A pair of biasing posts 188 extends outwardly, one for each side oflatch member 180. Collar ledge 174 of indicator collar 158 is engagedand secured by web 186 of latch member 180 when in an unactuatedposition of the latch member 180 as depicted in FIGS. 10-13. In theunactuated position of latch member 180 of indicator collar 158, theindicator collar 158 and thus obturator shield 106 is retained in afirst extended position. Latch member 180 is preferably molded as partof housing base 108 in cantilever fashion. However, latch member 180 maybe formed as a separate element and secured to base 108 by suitableknown techniques.

Slider 182 includes slider post 190 disposed at its lower end, armingbutton 192 extending distally from the distal face of slider 182 and apair of slider legs 194 which terminate in crooks 196. Crooks 196defined in slider legs 194 are configured and dimensioned to engageposts 188 of latch member 180, as shown in FIGS. 10 and 11. Slider 182is distally biased by slider spring 198 which is maintained in axialalignment by slider post 190 of slider 182. The proximal end of sliderspring 198 bears against the inner surface of control member 118 and ismaintained in position between slider post 190 and spring mount 146 ofthe control member 118. (See FIGS. 12 and 13). The distal biasing ofslider 182 causes arming button 192 to project through opening 108 aformed in housing base 108. The lower end or transverse leg 200 ofslider 182 resides with mounting posts 202 of housing base 108 (FIG. 3).

Referring now to FIGS. 3 and 12-13, obturator shield 106 has shieldlinkage 204 operatively connected thereto and along with the obturatorshield 106 defines an outer member of obturator assembly 100. In onepreferred embodiment, shield linkage 204 is connected to obturatorshield 106 through an arrangement including diametrical tabs 208extending from the distal end of shield linkage 204, which are receivedwithin corresponding openings 210 of obturator shield 106 in snaprelation therewith. Other means for connecting the components ofobturator shield 106 are also envisioned including snap fitarrangements, adhesives, welding tongue and groove arrangements, etc. Inother embodiments, obturator shield 106 and shield linkage 204 are asingle component. In the assembled condition, shield linkage 204 extendswithin housing base 108 and is at least partially received within collarextension 162. Shield linkage 204 includes a pair of diametricallyopposed outer grooves 212 which receive inner tabs 164 of collarextension 162 to operatively connect shield extension 204 and indicatorcollar 158. Thus, by virtue of connection of indicator collar 158 withshield linkage 204, obturator shield 106 and shield nose 206 are adaptedfor reciprocal axial movement along axis “x” and relative to obturatorhousing 102 and obturator shaft 104 concurrently with correspondingmovement of the indicator collar 158.

With reference again to FIGS. 1 and 2, shield nose 206 may be tapered,conical or frusto-conical in configuration, and is adapted to passthrough tissue and may be capable of cutting or piercing through tissue.In one preferred embodiment, shield nose 206 has an irregular shapedwith rounded tip 214. In particular, shield nose 206 is generallytapered in configuration defining a complex curved arrangement. As bestdepicted in FIG. 2, in a first profile of shield nose 206, the shieldnose 206 includes opposed concave surfaces 216. In a second profile(viewed at a 90° offset), shield nose 206 defines convex surfaces 218.This alternating concave and convex arrangement provides a substantiallyreduced profile (in cross-section) compared to conventional conicallyshaped obturators thereby providing an enhanced ability to penetrate orpass through tissue layers. Various radii of curvature are contemplated.Rounded tip 214, by its arcuate configuration, minimizes the potentialof undesired or unintended piercing of tissue. Alternatively, it isenvisioned that rounded tip 214 may be more pointed to also piercetissue if desired. This particular configuration of shield nose 206 isdisclosed in commonly assigned U.S. patent application Ser. No.11/103,892, filed Apr. 12, 2005, the contents of which are incorporatedin its entirety by reference herein. Shield nose 206 also defines knifeslot 220.

With reference to FIGS. 3, 6 and 13, the components of obturator shaft104 now will be discussed. Obturator shaft 104 includes obturator rod222 and blade 224 mounted to the obturator rod 222. Obturator rod 222defines proximal end 226 which passes through opening 160 of indicatorcollar 158 and is received within shaft mount 144 of control member 118.Proximal end 226 of obturator rod 222 includes circumferential recess228 which receives bifurcated tabs 148 of shaft mount 144 of controlmember 118 in snap relation therewith. In this manner, obturator rod 104is fixed to obturator housing 102.

With reference now to FIG. 12, in conjunction with FIG. 3, the distalend of obturator rod 222 defines obturator knife slot 230 having lockingprojection 232. Knife blade 224 may be secured within knife slot 230 byreception of locking projection 232 within knife aperture 234.Conventional means including adhesives, cements, etc. are alsoenvisioned. Knife blade 224 is preferably a flat or thin blade andfabricated from stainless steel by a suitable process, e.g., by stampingor metal injection molding and includes opposed cutting edges 236 whichextend to penetrating tip 238. Knife blade 224 is accommodated withinknife slot 220 of shield nose 206.

With reference now to FIGS. 14-15, a method of use and operation oftrocar assembly 10 will be discussed. Obturator assembly 100 has twomodes of operation. In the first mode of operation, obturator shield 106is locked in its distal position and nose shield 206 is applied againstthe tissue to penetrate or pass through the tissue through a blunt ordissecting entry. In the second mode, nose shield 206 and obturatorshield 106 are permitted to retract to expose knife blade 224 to contactand penetrate the tissue. Activator member 116 controls operation ofobturator assembly 100 between the two modes.

Initially, obturator assembly 100 is inserted within cannula assembly1000 and advanced to where obturator housing 102 is approximated withseal housing 2002 of the seal assembly 2000. Seal assembly 2000 maycomprise a separate part or may be a component of cannula assembly 1000.Seal housing 2002 and housing base 108 of obturator housing 102 may beappropriately dimensioned to form a friction fit or may be coupled toeach other by conventional means including bayonet coupling,tongue-groove, etc. With obturator housing 102 and seal housing 2002approximated, arming button 192 of slider 182 engages proximal surface2004 of seal housing 2002 and is forced upwardly (depicted bydirectional arrow “u”) from the position depicted in FIG. 13 to theposition depicted in FIGS. 14-15. During this movement, slider 182pivots or angulates whereby legs 194 of the slider 182 push latch member180 in a radial outward direction (depicted by directional arrow “z”)such that web portion 186 of latch member 180 is out of axial alignmentwith ledge 174 of indicator collar 158. In this position, indicatorcollar 158, obturator shield 106 and shield nose 206 are free to axiallymove provided activator member 116 is in the second mode of operation.With obturator assembly 100 mated with cannula assembly 2000, thesurgeon decides whether a blunt bladeless entry or a piercing bladeentry is required to access the surgical site. This decision may bepredicated on whether or not an initial entry opening has been madewithin the tissue, and, if so, thereby requiring a bladeless entry intothe tissue corresponding to the first mode of operation of obturatorassembly 100. If a bladeless or blunt entry is selected, the surgeonwill position activator member 116 in the initial position of FIG. 6. Inthis position, activator collar 122 is positioned over axial pin 170 ofindicator collar 158 and thus prevents proximal retracting movement ofthe indicator collar 158 and obturator shield 106. Visual confirmationof the positioning of activator collar 122 in the initial position isprovided by indicator arrow 128 of raised tab 124. In one preferredembodiment, the initial position of activator collar 122 corresponds torecessed arrow 128 being arranged in diametrical opposed relation toindicator flag 168 as shown in FIG. 6. The surgeon then applies shieldnose 206 to the tissue and exerts a distal force on the assembly 10.Shield nose 206 passes through tissue, e.g., by a blunt dissectingaction, to access the underlying surgical site, e.g., the abdominalcavity. Obturator assembly 100 may be removed from cannula assembly 1000and surgery may be performed with instruments introduced within cannulaassembly 1000.

If a bladed entry is required corresponding to the second mode ofoperation, activator member 116 is selectively moved from the initialposition of FIG. 6 to the release position of FIG. 16 by rotating theactivator member 116 about longitudinal axis “x” such that recessedarrow 128 of the activator member 116 is aligned with indicator flag 168thereby providing visual confirmation of the positioning of activatormember 116. Engagement of axial rib 122 of activator member 116 withwall 156 (FIG. 3) of control member 118 also provides tactileconfirmation of the positioning of activator member 116 in the releaseposition. In the release position, axial slot 130 of activator collar122 is in general alignment with axial pin 170 of indicator collar 158.

With reference now to FIGS. 17-19, the surgeon begins to insert trocarassembly 10 through the body wall of the patient. Shield nose 206contacts the tissue “t” and is driven upwardly to cause the shield nose206, obturator shield 106, and indicator collar 158 to move proximally(depicted by directional arrow “v”) against the bias of coil spring 178.As discussed hereinabove, obturator assembly 100 must be properly matedwith seal assembly 2000 such that the latching mechanism is activated topermit retraction of obturator shield 106. During the proximal movementof indicator collar 158, axial pin 170 of the indicator collar 158traverses secondary aperture 142 of control member 118 and traversesaxial slot 130 of activator member 116. (FIG. 19) Such movement exposesobturator blade 224 to incise the tissue. This armed condition ofobturator assembly 100 is visually verified by the proximal location ofindicator flag 168 of indicator collar 158. In addition, proximalmovement of indicator collar 158 causes posts 176 of the indicatorcollar 158 to ride along outer surfaces 194 a of legs 194 of slider 182to thereby move the slider 182 at least radially inwardly and upwardly(as shown by the directional arrows “r” and “v”, respectively) in ageneral aligned position relative to the obturator axis “x” anddisengaged from latch member 180. (i.e., crooks 196 of slider legs 194disengage posts 188 of latch member 180). With obturator blade 224exposed, the surgeon may apply a distally-directed force to obturatorassembly 100 to cause penetration through the tissue.

Once knife blade 224 and shield nose 206 pass through the body wall ofthe patient, indicator collar 158, obturator shield 106 and the shieldnose 206 move distally under the influence of coil spring 178 wherebythe shield nose 206 covers blade 224 as shown in FIG. 14. The obturatorassembly 100 may be removed from cannula assembly 1000 and surgery isperformed with instruments inserted through cannula assembly 1000. It isnoted that upon removal of obturator assembly 100, ledge 174 ofindicator collar 158 moves into engagement with web portion 186 of latchmember 180. Concurrently with this movement, slider 182, which isaligned relative to axis “x” as discussed hereinabove, is drivendistally under the influence of coil spring 198. In the respectivepositions of indicator collar 158 and slider 182 depicted in FIG. 13,collar ledge 174 of indicator collar 158 securely engages web 186 oflatch member 180 to secure shield nose 206 in its extended position.This feature ensures that the removed obturator assembly 100 will not bearmed.

Except where noted otherwise, the materials utilized in the componentsof the presently disclosed trocar assembly generally include materialssuch as, for example, ABS, polycarbonate, stainless steel, titanium andany other suitable biocompatible metals and/or polymeric materials. Apreferred ABS material is CYCOLAC which is available from GeneralElectric. A preferred polycarbonate material is also available fromGeneral Electric under the trademark LEXAN. An alternative polycarbonatematerial which may be utilized is CALIBRE polycarbonate available fromDow Chemical Company. The polycarbonate materials may be partially glassfilled for added strength.

Although the illustrative embodiments of the present disclosure havebeen described herein with reference to the accompanying drawings, it isto be understood that the disclosure is not limited to those preciseembodiments, and that various other changes and modifications may beeffected therein by one skilled in the art without departing from thescope or spirit of the disclosure.

What is claimed is:
 1. An obturator assembly for penetrating tissue andbeing at least partially positionable within a cannula assembly, whichcomprises: an obturator housing; an obturator shaft connected to theobturator housing and defining a longitudinal axis, and proximal anddistal ends; a penetrating member adjacent the distal end of theobturator shaft; an obturator shield mounted about the obturator shaftand having a distal shield nose, the obturator shield being adapted forlongitudinal movement between a fully extended position where thepenetrating member is substantially enclosed within the distal shieldnose and a fully retracted position where the penetrating member is atleast partially exposed from the distal shield nose; and a manuallymanipulative member mounted to the obturator housing and adapted forrotational movement about the longitudinal axis and relative to theobturator housing between an initial position corresponding to a firstmode of operation where the obturator shield is secured in the fullyextended position and the distal shield nose is used to penetratetissue, and a release position corresponding to a second mode ofoperation operatively releasing the obturator shield to permit theobturator shield to move repeatedly from the fully extended position tothe fully refracted position and back to the fully extended position,the obturator shield moving independent of the manually manipulativemember when in the second mode of operation.
 2. The obturator assemblyaccording to claim 1 further including a latch member disposed withinthe obturator housing, the latch member in operative engagement with theobturator shield to secure the obturator shield in the fully extendedposition thereof, the latch member being actuable to release theobturator shield to thereby permit movement of the obturator shieldtoward the fully retracted position provided the manually manipulativemember is in the release position thereof.
 3. The obturator assemblyaccording to claim 2 further comprising a release member mounted to theobturator housing and operatively coupled with the latch member, therelease member positioned to engage the cannula assembly upon mating ofthe obturator housing and the cannula assembly to thereby displace therelease member and cause actuation of the latch member.
 4. The obturatorassembly according to claim 1 including an indicator member operativelyconnected to the obturator shield, the indicator member being adaptedfor longitudinal movement with the obturator shield and for providingvisual confirmation to the operator of the positioning of the obturatorshield.
 5. The obturator assembly according to claim 4 wherein themanually manipulative member is in operative engagement with theindicator member when in the initial position of the manuallymanipulative member to secure the obturator shield in the fully extendedposition and being operatively disengaged from the indicator member whenin the release position of the manually manipulative member to permitmovement of the obturator shield to the fully retracted position.
 6. Theobturator assembly according to claim 5 including an indicator collardisposed within the obturator housing and mounted to the obturatorshield, the indicator collar having the indicator member mounted theretoand being adapted for longitudinal movement with the obturator shield.7. The obturator assembly according to claim 1 including stop meansassociated with the obturator housing for confirming positioning of themanually manipulative member at the initial position and the releaseposition.
 8. The obturator assembly according to claim 1 including acontrol member mounted in fixed relation to the obturator housing andoperatively associated with the manually manipulative member, one of thecontrol member and the manually manipulative member including a grooveand the other of the control member and the manually manipulative memberincluding a pin, the pin traversing the groove during rotation of themanually manipulative member between the initial and release positionthereof whereby terminating ends of the groove correspond to the initialand release position of the manually manipulative member.
 9. Theobturator assembly according to claim 1 wherein the penetrating memberis an obturator blade connected to the obturator shaft.
 10. Theobturator assembly according to claim 1 wherein the obturator shield isnormally biased toward the fully extended position.
 11. An obturatorassembly for penetrating tissue at least partially within a cannulaassembly, comprising: an obturator housing; an obturator shaft extendingdistally from the obturator housing and defining a longitudinal axis,the obturator shaft including a proximal end and a distal end; apenetrating member adjacent the distal end of the obturator shaft; anobturator shield mounted about the obturator shaft and having a distalshield nose, the obturator shield being adapted for longitudinalmovement between an extended position where the penetrating member issubstantially enclosed within the distal shield nose and a fullyretracted position where the penetrating member is at least partiallyexposed from the distal shield nose; and a manually manipulative membermounted to the obturator housing and adapted for movement about thelongitudinal axis and relative to the obturator housing between aninitial position corresponding to a first mode of operation where theobturator shield is secured in the extended position, and a releaseposition corresponding to a second mode of operation where the obturatorshield is repeatedly moveable relative to the manually manipulativemember between the extended position and the fully retracted position.12. The obturator assembly according to claim 11, further comprising alatch member disposed within the obturator housing, the latch member inoperative engagement with the obturator shield to secure the obturatorshield in the extended position thereof, the latch member being actuableto release the obturator shield to thereby permit movement of theobturator shield toward the fully retracted position provided themanually manipulative member is in the release position thereof.
 13. Theobturator assembly according to claim 11, further comprising stop meansassociated with the obturator housing for confirming positioning of themanually manipulative member at the initial position and the releaseposition.
 14. The obturator assembly according to claim 11, furthercomprising a control member mounted in fixed relation to the obturatorhousing and operatively associated with the manually manipulativemember, one of the control member or the manually manipulative memberincluding a groove and the other of the control member or the manuallymanipulative member including a pin, wherein the manipulative member isrotatable about the longitudinal axis, and wherein the pin traverses thegroove during rotation of the manually manipulative member between theinitial position and the release position thereof whereby terminatingends of the groove correspond to the initial position and the releaseposition of the manually manipulative member.
 15. The obturator assemblyaccording to claim 11, wherein the penetrating member is an obturatorblade connected to the obturator shaft.
 16. The obturator assemblyaccording to claim 11, wherein the obturator shield is normally biasedtoward the extended position.
 17. The obturator assembly according toclaim 11, wherein in the first mode of operation, the obturator shieldis secured in a fully extended position, and wherein in the second modeof operation, the obturator shield is repeatedly moveable relative tothe obturator shield between the fully extended position and the fullyretracted position.